diff --git a/.github/ci/doc.sh b/.github/ci/doc.sh
index 08d91f1..f13a209 100755
--- a/.github/ci/doc.sh
+++ b/.github/ci/doc.sh
@@ -6,6 +6,8 @@ set -euo pipefail
 export RUSTUP_HOME=/ci/cache/rustup
 export CARGO_HOME=/ci/cache/cargo
 export CARGO_TARGET_DIR=/ci/cache/target
+export BUILDER_THREADS=6
+export BUILDER_COMPRESS=true
 
 hashtime restore /ci/cache/filetime.json || true
 hashtime save /ci/cache/filetime.json